Thought you'd seen it all from Zac Brown Band? Oak Mountain show had usual strength, consistency -- and a surprise ending

BIRMINGHAM, Alabama -- First thing concertgoers had to notice, if they attended Zac Brown Band's June 6 performance at Oak Mountain Amphitheatre: The frontman is looking slimmer and trimmer.

Brown, 35, always has been a pleasantly chunky guy -- a natural condition, fans might assume, for a foodie and former chef. The bulk, the beard and the big smile were part of his Everyman appeal, even before the Georgia native made the leap to fame in 2008.

In fact, all of the guys in the Zac Brown Band have that same Average Joe quality; they're easy to like, easy to relate to, easy to cheer on. These eight musicians -- including Chris Fryar, a Birmingham native -- seem like neighborhood folks made good.

With every performance here, the Zac Brown Band seems to get stronger and tighter, more confident and unified. The group continues to refine its blend of country, Southern rock, bluegrass and tropical rhythms, mining jam-band influences and making occasional forays into R&B.

Singer-songwriter Brown might be the Man With the Plan -- heading up a company, Southern Ground, that encompasses music, food, film and more -- but he clearly appreciates the skills and abilities of his colleagues. As a result, each member of the Zac Brown Band has ample opportunity to shine.

No wonder Dave Grohl wanted to jump into the fray for the 2013 CMA Awards, teaming with the band for a new song, "Day for the Dead." Grohl -- the prime mover of Foo Fighters and, lest we forget, the former drummer for Nirvana -- also produced the band's four-track EP, "The Grohl Sessions: Vol. 1."

If Zac Brown Band needed any more street credibility, or a dose of rock star cool, this partnership certainly provided it. But if Grohl's absence was felt on the Oak Mountain tour stop, audience members didn't show it one bit.

They packed into the 10,500-seat amphitheater for songs such as "Knee Deep," "Colder Weather," "Toes," "Free," "Goodbye in Her Eyes," "Sweet Annie," "Keep Me in Mind," "Sic 'Em on a Chicken," "Highway 20 Ride" and "Chicken Fried."

Plenty of signature tunes were included on the setlist, along with covers of "Into the Mystic," "Can't You See," "The Devil Went Down to Georgia," "Enter Sandman" and "Grandma's Hands" (with guest artist Kristy Lee).

At one point, Brown recalled his past on Birmingham's concert scene, giving shout-outs to small venues such as Dave's Pub and The Nick. ("It wasn't that long ago that I was getting kicked out of Marty's," he said.) Brown thanked fans for their longtime support, and the party-hearty crowd responded with gusto.

Thunderstorms drenched the Birmingham area shortly before show time; Cook's opening set was cut short in the deluge. (He soldiered on, looking rather damp and disheveled.) Skies cleared, though, in time for a full set by the headliner -- and it was a two-hour goodie.

Final note: For the 2014 tour, a new element has come to the fore, emphasizing heavy-metal playfulness. Brown showed his theatrical side, emerging for the encore in a skeleton costume and mask that glowed in the dark. The other band members followed suit, digging into "Day for the Dead."

OK, so this common-sensical group is unlikely to rival The Flaming Lips for flamboyant showmanship. But as Friday's concert proved, Zac Brown Band still has the power to surprise us.